U.S. fixed mortgage rates kept unchanged from last week staying at a year's low level, said the Primary Mortgage Market Survey released Thursday by Freddie Mac, echoing an unstable recovery of housing market.

The U.S. mortgage giant said the 30-year fixed-rate mortgage ( FRM) in the week ending Thursday kept unchanged from last week staying at 4.13 percent, much lower than the 4.31 percent of the same period last year.

The 15-year FRM, a popular guide for those looking to refinance, edged up to 3.26 percent this week from 3.23 percent last week.

"Mortgage rates were little changed for the week with the 30- year fixed-rate mortgage remaining unchanged," said Freddie Mac's chief economist Frank Nothaft in a statement.

The five-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) rose from 2.97 percent last week to 2.99 percent this week, while the one-year Treasury-indexed ARM stayed at 2.39 percent, unchanged from last week.

The new home sales fell 8.1 percent in June on a monthly basis, said the U.S. Commerce Department on the same day, while the existing home sales in June increased 2.6 percent compared with May, reaching the highest pace since October 2013, the National Association of Realtors (NAR) said two days ago.

The recovery of U.S. housing market has showed signs of slowdown since the second half of last year, as sharp increases in home prices and limited inventories.